A 46-year-old woman from Mexico was found dead by humanitarian volunteers near the border wall east of Sásabe, Arizona on Monday morning. Her 15-year-old son ran to volunteers for help, saying his mother had stopped breathing while in a vehicle that had been speeding toward the wall from Mexico. A volunteer who examined her found no visible injuries and said she did not appear to have died from exposure, despite overnight lows of 19 degrees in the area. She remains unidentified, though she was carrying documents indicating she was from Mexico, and the cause of death may take weeks to determine.